Abu Humayd reported,

I heard him while he was among ten of the Companions of the Messenger of Allah ﷺ, one of them being Abu Qatada bin Rubai, who said, "I am the most knowledgeable of you regarding the prayer of the Messenger of Allah ﷺ. When he stood for prayer, he would stand upright and raise his hands until they were level with his shoulders, then he would say, 'Allahu Akbar.' When he intended to bow, he would raise his hands until they were level with his shoulders. When he said, 'Allah hears whoever praises Him,' he would raise his hands and stand upright. When he rose from the second rakah, he would say the takbir and raise his hands until they were level with his shoulders, just as he had done when he began the prayer."

Ibn Majah 862

Sahih

حدثنا محمد بن بشار حدثنا يحيى بن سعيد حدثنا عبد الحميد بن جعفر حدثنا محمد بن عمرو بن عطاء

عن أبي حميد الساعدي قال

سمعته وهو في عشرة من أصحاب رسول الله ﷺ أحدهم أبو قتادة بن ربعي قال أنا أعلمكم بصلاة رسول الله ﷺ كان إذا قام في الصلاة اعتدل قائما ورفع يديه حتى يحاذي بهما منكبيه ثم قال الله أكبر وإذا أراد أن يركع رفع يديه حتى يحاذي بهما منكبيه فإذا قال سمع الله لمن حمده رفع يديه فاعتدل فإذا قام من الثنتين كبر ورفع يديه حتى يحاذي منكبيه كما صنع حين افتتح الصلاة

ابن ماجه 862صحيح
Contents
Reference
Commentary
Ayat
Collection
Sunan Ibn Majah
Book
Establishing prayer and the sunnah regarding it
Chapter
Raising the hands when bowing and when raising the head from ruku
Numbering
Darussalam 862
Ibn Majah 862